ui: Use predefined zooming levels

src/libs/ui/mainwindow.cpp

@@ -29,6 +29,7 @@
 #include "searchitemdelegate.h"
 #include "settingsdialog.h"
 #include "qxtglobalshortcut/qxtglobalshortcut.h"
+#include "widgets/webview.h"
 
 #include <core/application.h>
 #include <core/settings.h>
@@ -84,7 +85,7 @@ struct TabState
         , expansions(other.expansions)
         , searchScrollPosition(other.searchScrollPosition)
         , tocScrollPosition(other.tocScrollPosition)
-        , webViewZoomFactor(other.webViewZoomFactor)
+        , zoomLevel(other.zoomLevel)
     {
         searchModel = new Registry::SearchModel(*other.searchModel);
         tocModel = new Registry::SearchModel(*other.tocModel);
@@ -145,7 +146,7 @@ struct TabState
     int tocScrollPosition = 0;
 
     QWebPage *webPage = nullptr;
-    int webViewZoomFactor = 0;
+    int zoomLevel = WebView::defaultZoomLevel();
 };
 
 } // namespace WidgetUi
@@ -651,7 +652,7 @@ void MainWindow::setupTabBar()
             previousTabState->selections = ui->treeView->selectionModel()->selectedIndexes();
             previousTabState->searchScrollPosition = ui->treeView->verticalScrollBar()->value();
             previousTabState->tocScrollPosition = ui->tocListView->verticalScrollBar()->value();
-            previousTabState->webViewZoomFactor = ui->webView->zoomFactor();
+            previousTabState->zoomLevel = ui->webView->zoomLevel();
         }
 
         // Load current tab state
@@ -673,7 +674,7 @@ void MainWindow::setupTabBar()
         ui->treeView->blockSignals(false);
 
         ui->webView->setPage(tabState->webPage);
-        ui->webView->setZoomFactor(tabState->webViewZoomFactor);
+        ui->webView->setZoomLevel(tabState->zoomLevel);
 
         ui->actionBack->setEnabled(ui->webView->canGoBack());
         ui->actionForward->setEnabled(ui->webView->canGoForward());

src/libs/ui/widgets/searchablewebview.cpp

@@ -68,14 +68,14 @@ void SearchableWebView::setPage(QWebPage *page)
     });
 }
 
-int SearchableWebView::zoomFactor() const
+int SearchableWebView::zoomLevel() const
 {
-    return m_webView->zealZoomFactor();
+    return m_webView->zoomLevel();
 }
 
-void SearchableWebView::setZoomFactor(int value)
+void SearchableWebView::setZoomLevel(int level)
 {
-    m_webView->setZealZoomFactor(value);
+    m_webView->setZoomLevel(level);
 }
 
 bool SearchableWebView::eventFilter(QObject *object, QEvent *event)

src/libs/ui/widgets/searchablewebview.h

@@ -48,8 +48,8 @@ public:
     bool canGoForward() const;
     void setPage(QWebPage *page);
 
-    int zoomFactor() const;
-    void setZoomFactor(int value);
+    int zoomLevel() const;
+    void setZoomLevel(int level);
 
     bool eventFilter(QObject *object, QEvent *event) override;
 

src/libs/ui/widgets/webview.cpp

@@ -36,15 +36,53 @@ WebView::WebView(QWidget *parent) :
 {
 }
 
-int WebView::zealZoomFactor() const
+int WebView::zoomLevel() const
 {
-    return m_zoomFactor;
+    return m_zoomLevel;
 }
 
-void WebView::setZealZoomFactor(int zf)
+void WebView::setZoomLevel(int level)
 {
-    m_zoomFactor = zf;
-    updateZoomFactor();
+    if (level == m_zoomLevel) {
+        return;
+    }
+
+    level = qMax(0, level);
+    level = qMin(level, availableZoomLevels().size() - 1);
+
+    m_zoomLevel = level;
+
+    setZoomFactor(availableZoomLevels().at(level) / 100.0);
+    emit zoomLevelChanged();
+}
+
+const QVector<int> &WebView::availableZoomLevels()
+{
+    static const QVector<int> zoomLevels = {30, 40, 50, 67, 80, 90, 100,
+                                            110, 120, 133, 150, 170, 200,
+                                            220, 233, 250, 270, 285, 300};
+    return zoomLevels;
+}
+
+const int WebView::defaultZoomLevel()
+{
+    static const int level = availableZoomLevels().indexOf(100);
+    return level;
+}
+
+void WebView::zoomIn()
+{
+    setZoomLevel(m_zoomLevel + 1);
+}
+
+void WebView::zoomOut()
+{
+    setZoomLevel(m_zoomLevel - 1);
+}
+
+void WebView::resetZoom()
+{
+    setZoomLevel(defaultZoomLevel());
 }
 
 QWebView *WebView::createWindow(QWebPage::WebWindowType type)
@@ -104,11 +142,22 @@ void WebView::mouseReleaseEvent(QMouseEvent *event)
 void WebView::wheelEvent(QWheelEvent *event)
 {
     if (event->modifiers() & Qt::ControlModifier) {
-        m_zoomFactor += event->delta() / 120;
-        updateZoomFactor();
-    } else {
-        QWebView::wheelEvent(event);
+        const QPoint angleDelta = event->angleDelta();
+        int delta = qAbs(angleDelta.x()) > qAbs(angleDelta.y()) ? angleDelta.x() : angleDelta.y();
+        const int direction = delta > 0 ? 1 : -1;
+
+        int levelDelta = 0;
+        while (delta * direction >= 120) {
+            levelDelta += direction;
+            delta -= 120 * direction;
+        }
+
+        setZoomLevel(m_zoomLevel + levelDelta);
+        event->accept();
+        return;
     }
+
+    QWebView::wheelEvent(event);
 }
 
 QUrl WebView::clickedLink(const QPoint &pos) const
@@ -119,8 +168,3 @@ QUrl WebView::clickedLink(const QPoint &pos) const
 
     return frame->hitTestContent(pos).linkUrl();
 }
-
-void WebView::updateZoomFactor()
-{
-    setZoomFactor(1 + m_zoomFactor / 10.);
-}

src/libs/ui/widgets/webview.h

@@ -24,6 +24,7 @@
 #ifndef ZEAL_WIDGETUI_WEBVIEW_H
 #define ZEAL_WIDGETUI_WEBVIEW_H
 
+#include <QVector>
 #include <QWebView>
 
 namespace Zeal {
@@ -35,8 +36,19 @@ class WebView : public QWebView
 public:
     explicit WebView(QWidget *parent = nullptr);
 
-    int zealZoomFactor() const;
-    void setZealZoomFactor(int zf);
+    int zoomLevel() const;
+    void setZoomLevel(int level);
+
+    static const QVector<int> &availableZoomLevels();
+    static const int defaultZoomLevel();
+
+public slots:
+    void zoomIn();
+    void zoomOut();
+    void resetZoom();
+
+signals:
+    void zoomLevelChanged();
 
 protected:
     QWebView *createWindow(QWebPage::WebWindowType type) override;
@@ -46,10 +58,9 @@ protected:
 
 private:
     QUrl clickedLink(const QPoint &pos) const;
-    void updateZoomFactor();
 
     QUrl m_clickedLink;
-    int m_zoomFactor = 0;
+    int m_zoomLevel = defaultZoomLevel();
 };
 
 } // namespace WidgetUi